title: Development of singlet oxygen absorption capacity (SOAC) assay method. 2. Measurements of the SOAC values for carotenoids and food extracts.
abstract: Recently a new assay method that can quantify the singlet oxygen absorption capacity (SOAC) of antioxidants was proposed. In the present work, kinetic study of the reaction of singlet oxygen ((1)O(2)) with carotenoids and vegetable extracts has been performed in ethanol/chloroform/D(2)O (50:50:1, v/v/v) solution at 35 °C. Measurements of the second-order rate constants (k(Q)(S)) and the SOAC values were performed for eight kinds of carotenoids and three kinds of vegetable extracts (red paprika, carrot, and tomato). Furthermore, measurements of the concentrations of the carotenoids included in vegetable extracts were performed, using a HPLC technique. From the results, it has been clarified that the total (1)O(2)-quenching activity (that is, the SOAC value) for vegetable extracts may be explained as the sum of the product {Σ k(Q)(Car-i)(S) [Car-i](i)} of the rate constant (k(Q)(Car-i)(S)) and the concentration ([Car (i)]) of carotenoids included in vegetable extracts.
authors.affiliation: Research Institute, Kagome Company Ltd., Nasushiobara-shi, Tochigi, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Aizawa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Aya
authors.initials: A
authors.lastname: Ouchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Inakuma
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Nagaoka
authors.forename: Junji
authors.initials: J
authors.lastname: Terao
authors.forename: Kazuo
authors.initials: K
authors.lastname: Mukai
mesh_terms: D002338:Carotenoids / Q000032:analysis* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D006207:Half-Life; D010936:Plant Extracts / Q000032:analysis* / Q000493:pharmacokinetics; D026082:Singlet Oxygen / Q000737:chemistry*; D014675:Vegetables / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D026082:Singlet Oxygen; D002338:Carotenoids